OK Tuners, Riddle Me This.....Hanging Burr

[Sibhusky]

And you're lightly running a gummi at 45° to the edge at the end of your tune? Just wondering if you've skipped that step and the burr is flexing down as you ski.

Is it just in spots or extended sections? I get the impression it's extended sections of the ski.

And how are you transporting your skis? Is the ski wrap at the contact point of the bases, separating them?

It just feels like if you're not scissoring them that many of the ideas here would produce short dings, not extended multi inch segments.

 

[Dakine]

No metal posts or chair foot rests at Nubs Nob.
I think I will use a gummi to dull them slightly and see what that does.
My edges are quite sharp and that may be a factor.
A small rock particle in the snow in the path of the edge could be the culprit and most of my skiing buddies don't keep their skis nearly as sharp as mine and don't see this.

 

[GregK]

No metal posts or chair foot rests at Nubs Nob.
I think I will use a gummi to dull them slightly and see what that does.
My edges are quite sharp and that may be a factor.
A small rock particle in the snow in the path of the edge could be the culprit and most of my skiing buddies don't keep their skis nearly as sharp as mine and don't see this.

Don’t detune with the Gummi, use a hard Gummi level with the edge to remove any nicks or burrs/micro burrs.
Think @ScottB was correct in the fact that you haven’t really removed the burr/micro burr and it’s gets more obvious after skiing a bit.

I was going to do a separate post about issues I had on two pairs of skis with micro burrs that hugely effected the glide of the skis. Thought it was an base issue as they were so slow even when going straight but it was micro burrs slowing the ski down.

Like you, I could feel the odd burr and thought I had removed it but it was still slightly there. When I felt the edge with a bare finger it seems okay but when I wrapped a cloth around my finger and then dragged it along the edge, it revealed more burrs. Correct with a gummy and test with a cloth and you should be golden.

I had a friend who sometimes skis with my regular group at one hill and skied with us last week. She’s a huge keener about skiing and ski tuning and was complaining about her edges not being sharp enough. I have a hard gummy Stone in my jacket and offered to do a 2 min job on the top of the hill. Found a few burrs but nothing major and the edges were nice and sharp after the Gummi. First run down and she’s 5mph plus faster on the flats then she’s ever been with the burrs removed. “This is unbelievable!” She kept saying and I noticed the same thing on my skis. So burrs are sometimes very noticeable and often mistaken for slow bases.

 

[James]

I had a friend who sometimes skis with my regular group at one hill and skied with us last week. She’s a huge keener about skiing and ski tuning and was complaining about her edges not being sharp enough. I have a hard gummy Stone in my jacket and offered to do a 2 min job on the top of the hill. Found a few burrs but nothing major and the edges were nice and sharp after the Gummi. First run down and she’s 5mph plus faster on the flats then she’s ever been with the burrs removed. “This is unbelievable!” She kept saying and I noticed the same thing on my skis. So burrs are sometimes very noticeable and often mistaken for slow bases.

So how were you removing the burrs? Going flat with hard gummi on base and side?

 

[GregK]

So how were you removing the burrs? Going flat with hard gummi on base and side?

Yes, hard Gummi on base and side with low pressure. Have seen others use a soft gummy on a 45 degree angle dragged across very lightly too but I prefer the hard Gummi flat as it leaves the edge sharp and works better on larger nicks.

 

[Dakine]

So how were you removing the burrs? Going flat with hard gummi on base and side?

I prefer to not use flexible abrasives at all.
I remove burrs with diamond stones, typically 800 or 1200 grit.
You guys have given me some good ideas.
When I tune I work the base and side edges alternately to minimize the burrs.
Just like sharpening a blade, you can't get it sharp by only working one side.

 

[James]

Burrs on knives are a big deal. Running the blade through soft wood or very hard felt is the usual removal method. But those are very acute angles.
Racers I’ve known generally use the hard stone/ceramic stone/fine diamond stone on base to remove or make sure there are no hangers. They worry about that almost as much as how sharp they are.

 

[GregK]

I prefer to not use flexible abrasives at all.
I remove burrs with diamond stones, typically 800 or 1200 grit.
You guys have given me some good ideas.
When I tune I work the base and side edges alternately to minimize the burrs.
Just like sharpening a blade, you can't get it sharp by only working one side.

Higher grit diamond stones good for burrs too. I’m a professional car detailer and you always use the least aggressive polish/compounds that will remove the scratch and then go more aggressive if needed. So if a gummi removes it, I’m good. If not, move up to high grit diamond stone then lower grit diamond and then file if it’s really bad.

Then to finish off the edge(or car paint) you go in reverse order ending with least aggressive Diamond Stone/Gummi to finish off the edge.

The “cloth dragging test” was a game changer for me testing for smaller burrs if you don’t have a microscope on the edges. Was shocking how much slower my skis were with the micro burrs so I could see why racers are fanatical about removing them!

 

[Jacques]

Just freehand some ceramic stone to clean it up and ski!!!!
Post filing burr shown here.

 

[Sibhusky]

When I'm lightly (no pressure) running a gummi at 45° it's a hard gummi, and it's just to knock off the micro burr not detune. I'm barely resting it on the edge. You'd almost say, why bother?

 

[Dakine]

Has this been the most obscure Tuning thread on Pugski?

 

[oldschoolskier]

Burrs are cause when metal is dragged off an edge. If the metal is remove into the edge that chance of a burr is slim to none. This is simple metal working.

If you leave such a fine burr that you don’t detect before skiing, skiing will not make it bigger, it will actual remove it because the snow (ice crystals) are a fine abrasive.

So if using a file ensure it cuts into the edge, stones typically leave significantly small burrs and as with files ensure you cut into the edge to prevent burrs.

Personally, gummy stones are a preference of the individual, personally I don’t use them, if anything on tooling (part if my work) I use a 1000grit diamond file just to touch up and clean. Too much coarser and it can change edge shape, to much finer, too slow.

 

[Atomicman]

Like Scott B. I have never had this happen from just skiing. Does it affect the performance (grabby) or just able to fell it with your fingernail/

 

[Dakine]

Doesn't seem to affect turning but glide seems down.
It is at most .005" high.

 

[Doug Briggs]

Pictures of your structure would help to eliminate that as a cause of problems.

 

[Sibhusky]

Pictures of your structure would help to eliminate that as a cause of problems.

See attachment

Once I hone it down, it still comes back but not as much,
I don't have a macro lens but in this shot you can see how it shaved my fingernail.
It is a pretty small burr that doesn''t seem to affect the ski but it bugs me I can't explain it.

View attachment 91285

 

[Dakine]

@DougBriggs...there is a pic of structure in post #6.
Nothing abnormal about the structures.
The one in the #6 pic is a medium chevron structure that came on the Blossom White Outs.
My RX Kastles with a linear structure do the same thing.

 

[Atomicman]

Gummis are not for removing a hanging burr. All you are going to do is slightly dull the edge, because even a hard blue gummi is soft and will hang over the edge point. Particularly if you are using enough pressure to try to remove a hanging burr. You should be using a true hardstone. I use a surgical stone to remove hanging burrs. And a Hanging burr is NOT a microburr as such. This is where sibhusky and I are on the same page. A micro burr is a extremely slight burr on the edge point. ....this is why we use an absolutely no pressure approach with a hard gummi at a 45 degree angle to the edge point as the very final step in the tuning process.

And I am sorry oldschooler, but a hanging burr will NOT break-off from skiing on it. Any burr created from working on the base edge will break off because it is sticking straight out from the base edge 90 degrees to the side edge. When the ski is rolled on edge it breaks off. Not so with a hanging burr created from working the side edge. It goes straight down into the snow, 90 degrees to the base edge and plays havoc with rolling the ski on and off edge. I have NEVER had a ski with a hanging burr improve by skiing on it!

 

[Doug Briggs]

@DougBriggs...there is a pic of structure in post #6.
Nothing abnormal about the structures.
The one in the #6 pic is a medium chevron structure that came on the Blossom White Outs.
My RX Kastles with a linear structure do the same thing.

Sorry I didn't see it there. That is a fairly deep structure in my opinion. I wouldn't use that for anything but spring conditions here in Colorado. Don't know where you are

 

[Sibhusky]

Sorry I didn't see it there. That is a fairly deep structure in my opinion. I wouldn't use that for anything but spring conditions here in Colorado. Don't know where you are

I'm going to guess Michigan, since he says Tip of the Mitt. Lots wetter snow I would guess.

But he's not worrying about structure, he's worrying about the cause of a burr he can feel, and which keeps returning

Beer league racing and gates?